Positional Relationship between Two Microcatheters according to the Navigation Sequence within the Curved Vessel in Neuroendovascular Procedures.

Objective In neuroendovascular treatment, there are many opportunities to guide multiple catheters into the intracranial blood vessels. We report the relationship between two microcatheters according to the guiding order with experimental in vitro studies. Materials and Methods We hypothesize that in a bent blood vessel such as a paraclinoid region of the internal carotid artery, the catheter that was first guided tended to pass through the inside, and the catheter that was guided later tended to pass through the outside. The in vitro verification was performed using a microcatheter and a balloon catheter in a silicone vascular aneurysmal model. Results As a result, it was found that the two catheters were arranged according to our hypothesis. This finding was also observed during the actual operation of balloon-assisted coil embolization. Conclusion The positional relationship between the two catheters according to the navigation order is very important, in particular during balloon-assisted coiling and stent-assisted coiling via a jailed microcatheter.

A novel remote hands-on training for neuroendovascular-based treatment in the era of the COVID-19 pandemic.

The COVID-19 pandemic has demanded a change in learning modalities, which led us to develop a remote personal training system for clinicians performing neuroendovascular procedures. A portable vascular model designed for practicing catheter navigation guidance, thrombus retrieval, and intracranial aneurysm coil embolisation was established. We created an environment that enabled interactive dialogue and communication across long distances using the Internet. The instructor conducted approximately 2 h of hands-on training with two to four trainees at a time. Despite the restrictions enforced by the Government of Japan due to the COVID-19 pandemic, 17 online hands-on training were successfully conducted throughout Japan over 1 year for a total of 48 trainees. The developed remote training programme, to avoid the aggregation of a large number of trainees at a developed time, proved to be at par with the conventional learning system. The training was well-received since the operation time was longer and the question and answer sessions were more fulfilling compared to the conventional format in which a group of trainees had got a brief opportunity to receive actual hands-on experience.

Usefulness of a Curved Multiple Reconstruction Image for Transarterial Intravenous Coil Embolization of a Dural Arteriovenous Fistula of the Sphenobasal Vein: A Case Report.

Hemorrhagic isolated dural arteriovenous fistulas (DAVFs) are often challenging to treat. Here, we report a case of the lateral cavernous sinus (CS) DAVF successfully treated by transarterial intravenous coil embolization using a curved multiplanar reconstruction (MPR) image assistance. A 54-year-old man presented with a severe headache and was diagnosed with subarachnoid hemorrhage caused by CSDAVF. Angiography indicated that the fistula was fed by branches of the left external carotid artery and drained into cortical veins. There were multiple shunting points at the left sphenobasal vein accompanied by varicose veins. Using curved MPR images, the left accessory meningeal artery was chosen for the endovascular approach into the affected veins, including ruptured varix. The shunt was completely occluded by detachable coils. When the curved MPR image indicates a developing feeding artery and a large shunting point, transarterial intravenous coil embolization becomes a good treatment option for CSDAVF, which has no venous access.